Despite new advances in medical imaging, projection radiography continues to be an important tool for detection of pulmonary diseases including lung cancer, interstitial lung diseases, as well as a variety of other thoracic diseases. Conventional chest radiography techniques rely on the use of a screen-film combination as the image receptor. Various digital radiography techniques have been developed and investigated to improve the quality, display, processing, utilization and management of radiographic images. Among them, computed radiography (CR) has become a promising candidate for large scale implementation of digital radiography and integration with a Picture Archival and Communication System (PACS) and has found wide use in bedside chest imaging in intensive care units (ICUs). However, current CR systems, due to its single screen design, have intrinsically lower detection quantum efficiency (DQE) and spatial resolution than the conventional screen film techniques. Partially for these reasons, they have not replaced screen-film techniques in chest radiography for primary diagnosis of pulmonary diseases. In this project, the applicants proposed to use a high resolution (HR) screen and a standard resolution (ST) screen to simultaneously acquire a high resolution front image and a standard resolution, low noise back image. These two images are superimposed to construct an image of improved DQE and spatial resolution. This technique referred to as the asymmetric dual-screen CR technique, will be optimized and tested using an experimental CR imaging system. Image properties of the optimized dual-screen CR images will be characterized by measuring the signal response, MTF, and noise properties. A comprehensive patient study will be conducted to evaluate and compare the duel-screen CR techniques with the single-screen CR and conventional screen-film techniques. Success of this project could result in a CR technique with a spatial resolution and DQE comparable to or even superior than those of the conventional screen-film techniques. The asymmetric dual-screen CR technique should help upgrade the quality of CR chest images substantially and lead to improved accuracy for primary diagnosis of pulmonary diseases.